A. Field of the Invention
An embodiment of the present invention relates to an apparatus for correcting deflection in an open width stabilizer, and more particularly, an embodiment of the present invention relates to an apparatus for correcting deflection in small diameter rolls of an open width stabilizer so as to create a straight line nip with uniform pressure across the nip.
B. Description of the Prior Art
Circulatory knit fabric produced in the U.S. has mostly been finished in tubular form. Machinery has been developed around an internal spreader to propel the fabric through various finishing operations, such as steaming and compacting, to reduce length shrinkage.
In contrast, Europeans slit the fabric tube, open it, and finish the fabric in open width using mostly woven good finishing equipment, such as tenter frames and belt compactors, some modified to accommodate the elastic nature of the knit construction. To control length shrinkage, the Europeans use various versions of a belt compactor or sanforizing machines, none of which can reduce shrinkage to less than the 5% that is required by most world wide garment manufacturers.
Americans developed a two-roll compactor for tubular fabric, with one roll feeding the fabric at a given speed, and with a second retarding roll slowing the fabric travel to compact the fabric in its length, thus reducing length shrinkage, as required, to a zero length shrinkage on some fabrics.
When the two-roll principal was tried on wide open width circular knits, it became apparent that the rolls would have to be made larger in diameter to reduce deflection, however, this created a wider nip area where the fabric has to change its length dimension, causing objectionable friction on the fabric, resulting in poor quality.
Catallo used a small diameter roll and overcame the deflection problem by bending the rolls to produce a straight nip. A way to do this at the time was by using a wedge between the ends of the rolls, as taught by U.S. Pat. No. 5,553,365 to Catallo. When this system was used in production, however, quality of the fabric was not always acceptable in the full width of the fabric, and it was determined that the nip was not uniform as a result of the wedge's reaction forces to bend the rolls. The rolls were not bent on the nip line, but deflected downward, changing the nip line in the center of the rolls.
The apparatus taught by U.S. Pat. No. 5,553,365 to Catallo can best be seen in FIGS. 1-3, which are, respectively, a diagrammatic perspective view of a prior art two-roll fabric shrinker, an enlarged diagrammatic end view of the area generally enclosed by 1 dotted curve identified by ARROW 2 in FIG. 1, and a diagrammatic top plan view taken generally in the direction of ARROW 3 in FIG. 2, and as such, will be discussed with reference thereto.
As shown in FIG. 1, a prior art shrinker is shown generally at 10 for a fabric web material, and comprises a feed roll 14, a retard roll 16, and an apparatus 18 for adjusting deflection of the feed roll 14 and the retard roll 16 to thereby maintain a desired size to a passageway 20 between the feed roll 14 and the retard roll 16 to optimize compaction of the fabric web material. The feed roll 14 has a pair of ends 22, with only one being shown, and the retard roll 16 has a pair of ends 24, with only one being shown.
The apparatus 18 comprises bearings 26. The bearings 26 of the apparatus 18 are mounted to the pair of ends 22 of the feed roll 14, respectively, with only one being shown. The apparatus 18 further comprises lever bearings 28. The lever bearings 28 of the apparatus 18 are mounted to the pair of ends 24 of the retard roll 16, respectively, with only one being shown. The bearings 26 of the apparatus 18 are in a form of pillow block bearings 29.
The apparatus 18 further comprises a pneumatic cylinder 30, and a shaft 32 having an upper end 34 and a lower end 36. The upper end 34 of the shaft 32 of the apparatus 18 is connected to the lever bearings 28 of the apparatus 18, and the lower end 36 of the shaft 32 of the apparatus 18 is connected to the pneumatic cylinder 30 of the apparatus 18.
By providing for the pivoting of the lever bearings 28 of the apparatus 18 by moving the shaft 32 of the apparatus 18, the feed roll 14 and the retard roll 16 are allowed to move towards or away from one another, thereby changing the desired size of the passageway 20,
The apparatus 18 further comprises the feed roll 14 having an axial shaft 38, the retard roll 16 having an axial shaft 40, a feed roller bearing 42, a retard roller bearing 44, and a symmetrical wedge-like member 46.
The feed roller bearing 42 of the apparatus 18 is connected to the axial shaft 38 of the feed roll 14 of the apparatus 18, and the retard roller bearing 44 is connected to the axial shaft 40 of the retard roll 16 of the apparatus 18. The symmetrical wedge-like member 46 of the apparatus 18 is disposed between, and in moving relationship to, the feed roller bearing 42 of the apparatus 18 and the retard roller bearing 44 of the apparatus 18.
As shown in FIG. 2, the symmetrical wedge-like member 46 of the apparatus 18 is a relatively thin solid in front view, and defined by a bottom 52, a top 54, a feed side 56, and a retard side 58. The bottom 52 of the symmetrical wedge-like member 46 of the apparatus 18 is straight and horizontally oriented. The top 54 of the symmetrical wedge-like member 46 of the apparatus 18 is straight, horizontally oriented, and above, parallel to, shorter than, and centered on, the bottom 52 of the symmetrical wedge-like member 46 of the apparatus 18. The feed side 56 of the symmetrical wedge-like member 46 of the apparatus 18 engages the feed roller bearing 42 of the apparatus 18, while the retard side 58 of the symmetrical wedge-like member 46 of the apparatus 18 engages the retard roller bearing 44 of the apparatus 18. The feed side 56 of the symmetrical wedge-like member 46 of the apparatus 18 and the retard side 58 of the symmetrical wedge-like member 46 of the apparatus 18 are of equal length, reciprocally skewed, and extend from the bottom 52 of the symmetrical wedge-like member 46 of the apparatus 18 to the top 54 of the symmetrical wedge-like member 46 of the apparatus 18 so that no corners 60 of the symmetrical wedge-like member 46 of the apparatus 18 are 90°.
The symmetrical wedge-like member 46 of the apparatus 18 exerts reaction forces 48 against the feed roller bearing 42 of the apparatus 18 and the retard roller bearing 44 of the apparatus 18 in response to forces 50 exerted thereon by the feed roller bearing 42 of the apparatus 18 and the retard roller bearing 44 of the apparatus 18, with the reaction forces 48 acting on identical elevations 51 on the feed side 56 of the symmetrical wedge-like member 46 of the apparatus 18 and the retard side 58 of the symmetrical wedge-like member 46 of the apparatus 18 due to the symmetry of the symmetrical wedge-like member 46 of the apparatus 18, and as shown in FIG. 3, the reaction forces 48 cause the feed roll 14 and the retard roll 16 to deflect downwardly, thereby changing the nip in the center of the feed roll 14 and the retard roll 16 so as to form a non-uniform nip.
Adjustment of the pneumatic cylinder 36 of the apparatus 18 causes movement of the lever bearings 28 of the apparatus 18 to move the feed roll 14 and the retard roll 16.